This invention relates to method and apparatus for introducing a sample to be analyzed through an introduction aperture into a graphite tube of a heated graphite atomizer of a flameless atomic absorption spectrometer.
In flameless atomic absorption, the atomic cloud, whose absorption is measured, is generated in a graphite tube of a heated graphite atomizer. The sample to be analyzed is in general introduced through a wall aperture into the graphite tube. Only very small quantities, of the order of up to about 20 microliters, for example, are normally introduced by means of a micro-pipette into the graphite tube. However, this procedure has certain disadvantages when carrying out a series of atomic absorption measurements, as an unproportionately large amount of time and the continous presence of an operator are required. It is known from gas chromatography, as referred to in German AS 1 157 817, to use so-called micro-dipper bars instead of micro-pipettes, i.e. capillary containers into which liquid volumes of up to 20 microliters are aspirated by means of capillary action.
An object of the present invention resides in the provision of a procedure and a device of the above-mentioned type which, with the use of sample containers open at both ends, carries out an automated measuring series.